Friday, August 22, 2008

Snapping Hip- Internal or External?

High-performance athletes learn to live with many injuries. I am always amazed to see what the joints of some professional athletes look like- many of them are walking around with pain that would make me admit myself to the hospital for a pain pump.

Some ailments are more confusing to diagnose than others. In the "snapping hip" syndrome, there is an audible snap or click that occurs in the region of the hip joint. Athletes that are particularly prone to this sydrome include ballet dancers, track and field competitors, soccer players, and gymnasts, where repetitive hip flexion is common.

Snapping hips can be caused by intraarticular and extraarticular conditions. The most common intraarticular cause is a tear of the acetabular labrum. There are many extraarticular causes, including movement of the iliotibial band over the greater trochanter, snapping of the iliopsoas tendon, and movement of the gluteus maximus tendon over the greater trochanter.

15 year-old female with snapping left hip, referred for MRI to see if snapping is intraarticular (usually due to a labral tear) or extraarticular in origin. Oblique axial T2-weighted image reveals local soft tissue edema (red arrow) associated with the iliopsoas tendon (yellow arrow):

The iliopsoas tendon can snap over the lesser trochanter, the joint capsule, or the iliopectineal eminence. With reptitive snapping, the local soft tissues can become edematous, as in this case. The iliopsoas bursa can also become inflamed.

Oblique coronal T2-weighted image confirms the edema (red arrow) tracking along the iliopsoas tendon (yellow arrow):

Axial T2-weighted image depicts the unilateral nature of the edema (red arrow) associated with the left iliopsoas tendon (yellow arrow). Note the normal right iliopsoas tendon (green arrow):

Snapping can be asymptomatic, but can be painful in some patients. Althoug nonoperative treatment is usually successful, in recalcitrant cases, one can perform a total or partial release of the posteromedial tendinous portion of the iliopsoas muscle at the pelvic brim.

Vic David MD

No comments: